Automatic throttle control



Feb 17, 1942.

c. J. CRANE ET AL AUTOMATIC THROTTLE CONTROL Filed July 18, 1939 asJmvg In]:

lzvme/vroes (TEA/v5 624,? c). 6250265 1?. LARK/N Patent ed Feb. 17, 1942'.

AUTOMATIC THROTTLE CONTROL Carl J. Crane and George R. Larkin,

Dayton, Ohio Application July 18, 1939, Serial No. 285,206

(Granted under the act of March 3, .1883, as amended April 30, 1928 370 0. G. 757) 6 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, Without the payment'to us of any royalty thereon.

This invention relates to an improved throttle control for the engines of aircraft.

It is an object of our invention to so correlate an anemometer means, a speed reference means and a throttle control mechanism that an out of phase relationship of the anemometer means and speed reference means causes an actuation of the throttle control mechanism to increase or decrease the fuel input to the engines resulting in maintaining the aircraft at a predetermined true air speed.

It is also an object of this invention to so control mechanism that an out of phase relationship of said two means results in the actuation of the throttle control mechanism for controlling the driving engines to maintain the conassociate a velocity actuated speed controlledmeans, a constant speed means and a throttle stant speed means and the speed controlled means in phase.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing, it being clearly understood that the same are by way of illustration and example only and are not to be taken as in any way limiting the spirit or scope of this invention. The spirit and scope of this invention is to 1 be limited only by the prior art and by the term of the appended claims.

In the drawing: Fig. l is a diagrammatic layout of the device, showing the speed reference means, the throttle valve control mechanism and the anemometer means which includes a speed controlled means;

and

Fig. 2 is an elevational view of the constant speed reference means {and the speed controlled means.

Referringto the drawing, the anemometer which, as is well known, conwheel II is advanced or rotated one notch by controlled means, is mounted on shaft IS with freedom for rotative movement and is frictionally held against collar I4 by spring I6. Collar I4 is rigidly attached to shaft I5 to rotate therewith.

Contact II, integral with ratchet wheel H, ex-

tends between electrical contacts I9 and 20, fastened to and insulated from collar I4. Contacts I9 and are electrically connected to contact rings 2I and 22 respectively, which, in turn, are rigidly mounted on and insulated from shaft I5. A brush 23 engages contact ring 2|, while brush 24 engages contact ring 22. Brush 25 engages shaft I5 to establish an electrical circuit between a source of electrical energy 26 and a reversing motor 21, which, through gears 28 and 29, operates a carburetor throttle control member 3 I.'I. Shaft I5, and consequently collar I4, are caused to rotate'a't a constant rate of speed by motor 3| and gears 32 and 33. A tachometer 34 registers the speed of motor 3| and a rheostat 35 is'used to preset the speed of the motor toany desired amount. Brushes 23, 24 and 25 are mounted on and insulated from plate I8.

The operation ofthe device is as follows: The rheostat 35- is set so that motor 3|, shaft I5 and collar I4 operate at the speed desired. Each rotation of cam 4 in response to rotation of anemometerblade I causes lever arm 8 to advance is the blade of stitutes a means for indicating a true air speed Y irrespective of temperature or pressure conditions. Rotation of blade I causes .a rotation of gears- 2 and 3 and cam 4 to makeand break contacts 5 and 6. Each-time the contacts are ratchet wheel II one notch. As longas the true air speed remains constant, wheel II and collar I4 move at the same speed and contact I! is-maintained'between and out of engagement with contacts I9 and 20. Consequently, motor 21 is inoperative and throttle control member 30 remains in the same position. However, should the air speed of theplane becomeless than that set by the motor 3|, ratchet wheel closed, solenoid I is energized, drawing the upper end of lever 8 in a counterclockwise direction about its pivot against the action of spring 9 to actuate spring pressed pawl II), pivotally mounted on the lower end of lever 8. Ratchet II will lag, contacts I! and I9 will engage and motor 21 will become throttle valve control member 30 to provide more fuel to the engines. This will, of course, increase the air speed of the plane until the ratchet wheel II is actuated at a speed to separate contact II from contact I9. 'Should the plane operate at a speed in excess of the desired amount,

energized to operate maintaining an aircraft at a true air speed comprising, anemometer means for registering the true airspeed of the aircraft, a ratchet wheel actuated by said anemometer means, constant speed reference means comprising a motor driven shaft having a collar integral therewith, said ratchet wheel being rotatably mounted on said shaft and spring pressed against said collar, spaced electrical contacts on said collar, a single electrical contact on said ratchet wheel, a reversible motor electrically connected to said contacts, a throttle control mechanism operated by said motor, whereby upon a difference of movement between the ratchet wheel and collar the single contact engages one of they on said controlled means and said speed reference means electrically connected to said motor, said contacts being spaced apart when said air speed controlled means .and said constant speed spaced contacts to establish an electric current to said motor thereby actuating said throttle control mechanism to maintain the aircraft at substantially the constant speed of the reference means.

2. Apparatus for controlling the fuelinput to an aircraft engine to maintain said aircraft at a constant air speed comprising, a throttle control mechanism, a reversible motor operatively connected to said mechanism, a shaft, means for rotating said shaft at a predetermined speed to establish a constant speed reference means, a ratchet wheel frictionally held in engagement with said shaft with freedom for rotative movement, anemometer means for registering the true air speed of the aircraft, means operated by said anemometer means for rotating said ratchet wheel, an electrical contact on said ratchet wheel electrically connected to said motor, spaced apart contacts mounted on said shaft and electrically connected to said motor, said ratchet wheel contact being fioatingly received between said spaced contacts so that when said ratchet wheel and shaft are rotating at the same speed the motor circuit is open, and when said ratchet wheel and reference means are in phase and certain of said contacts being in engagementwhen said controlled means and reference means are out of phase to operate said motor to establish an in phase relationship.

4. Apparatus for maintaining an aircraft at a true air speed comprising, a throttle valve controlling member, a reversible motor for actuating said member for controlling fuel input to the internal combustion engines driving said aircraft, an anemometer controlled speed means operating as a function of the true air speed of said aircraft, a constant speed reference means associated with said speed controlled means, electrical contacts on said speed controlledmeans and said speed reference means for controlling the flow of current to said motor, said contacts being separated when the true airspeed and the speed reference means substantially coincide and certain of said contacts being in engagement to establish a circuit to said motor for actuating said throttle control mechanism to maintain'the aircraft at substantially the constant speed of the reference means.

5.- Apparatus for maintaining an aircraft at a predetermined true air speed comprising, a driving engine, a throttle valve control mechanism for said driving engine, an air velocity responsive device including an anemometer, a constant speed means, said constant speed means and air velocity responsive device being correlated with said throttle valve control mechanism to operate upon a difference between the constant speed means and the velocity responsive device to actuate said throttle valve control mechanism to maintain a substantial coincidence of said constant speed means and said velocity responsive device.

6. Apparatus for maintaining an aircraft at a true air speed comprising, a throttle valve means for controlling the fuel input to a driving engine, revoluble constant speed reference means, 9. revoluble air speed controlled means responsive to the true air speed of the aircraft, said constant speed reference means, air speed controlled means, and throttle valve means being so constructed and arranged that lack of identity of the speed reference means and the air speed controlled means results in the operation of said throttle valve to control the input of fuel to said engines to establish identity of said reference means and said controlled means.

- CARL J. CRANE.

GEORGE R. LARKIN. 

